Make various string_util functions take StringPieces instead of char[].

extensions/common/permissions/socket_permission_entry.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/common/permissions/socket_permission_entry.h"
 
 #include <cstdlib>
 #include <sstream>
 #include <vector>
 
@@ skipping 10 matching lines @@
 
 using content::SocketPermissionRequest;
 
 const char kColon = ':';
 const char kDot = '.';
 const char kWildcard[] = "*";
 const int kWildcardPortNumber = 0;
 const int kInvalidPort = -1;
 
 bool StartsOrEndsWithWhitespace(const std::string& str) {
-  if (str.find_first_not_of(base::kWhitespaceASCII) != 0)
-    return true;
-  if (str.find_last_not_of(base::kWhitespaceASCII) != str.length() - 1)
-    return true;
-  return false;
+  return !str.empty() &&
+      (IsWhitespace(str[0]) || IsWhitespace(str[str.length() - 1]));
 }
 
 }  // namespace
 
 namespace extensions {
 
 SocketPermissionEntry::SocketPermissionEntry()
     : pattern_(SocketPermissionRequest::NONE, std::string(), kInvalidPort),
       match_subdomains_(false) {}
 
@@ skipping 171 matching lines @@
 
   if (pattern_.port == kWildcardPortNumber)
     result.append(1, kColon).append(kWildcard);
   else
     result.append(1, kColon).append(base::IntToString(pattern_.port));
 
   return result;
 }
 
 }  // namespace extensions